The present invention relates to a surveillance system having a remotely controlled vehicle for use in hazardous environments, such as nuclear power facilities and toxic chemical manufacturing operations, the vehicle being adapted to monitor a wide variety of environmental conditions and to have optimum mobility throughout a facility.
The environmental dangers related to nuclear power plants, hazardous chemical production and storage facilities, hazardous waste storage areas and industrial spills, are well known. Often, the solution to environmentally hazardous problems requires both an initial analysis and continued monitoring of the environment, including the operational condition of machinery, valves, gauges and the like, without the exposure of personnel to the related environmental dangers. It also is desirable to have the capability to take multiple samples from the wall, floor and equipment surfaces of a contaminated facility. Subsequent corrective action must be taken to solve the underlying problem. The use of a remotely controlled robot to examine a damaged nuclear power plant and to take corrective action to repair damage which may have been caused to the plant facility is shown in the publication entitled "Nuclear Power Plant Emergency Damage Control Robot", Gupton, Robotic Age, pages 18-21 (March/April 1983). The proposed vehicle has motors, lights, electronic equipment, a communications capability, which also include video transmission capabilities, and batteries for operation remote from a source of high power. However, this and similar prior art systems teach the use of large, heavy and complex mobile vehicles which normally are tethered to a central control facility by a cable that provides both power and a communications/control capability. These vehicles are very expensive and their broad range of capabilities requires a substantial structure weighing several tons and having significant power requirements. Moreover, such vehicles often are limited to predetermined paths and lack the mobility required in multilevel facilities as well as the maneuverability required to move through tight passages, under equipment and around barriers. Notwithstanding their substantial cost, they have significant limitations that prevent them from being cost effective. A more manageable, remotely-controlled robot system in shown in the publication, "Ferngelenktes Manipulator--Fahrzeug MF3", Kohler, VDI-Z 120 No. 22 (November 1978). There, a tethered, remotely-controlled robot is configured to have four independently operating drive track mechanisms each of which supports one corner of a rectangular payload platform. Each drive mechanism comprises a continuous tread belt which is wrapped around a drive sprocket, driving wheels and tensioner wheel. The payload platform is equipped with one or two articulated manipulator arms that can be adapted to perform a variety of complex end-effect functions, including holding, lifting, welding and drilling. The payload platform also contains lights and a pair of television cameras which are adapted to provide a stereo-optic view capability to a remote control station. At the control station, an operator may use the stereo-optic viewer and a "joystick" control to operate the device. The robot is sized to move through doorways and has a stair-climbing capability which enables it to move about a multilevel facility; however, the vehicle cannot negotiate stairways with small landings. This and similar structures taught in the prior art continue to be complex, weighing a substantial amount and having a weight and length which restricts their maneuverability. Moreover, the prior art teaches mobile vehicles that are tethered by power and telecommunications cables, which provide a further restriction on their maneuverability and the danger of snagging, particularly when moving to another level in a multilevel facility. Additionally, no prior art structure has the capability of obtaining samples from various surfaces within a facility on a repetitive basis, other than through the grabbing capability of an articulated arm with clamping extremities. Finally, all of the prior art devices are complex and, necessarily expensive to manufacture and maintain.
In order to solve the problems confronted by the prior art, the present invention teaches a surveillance system having a unique remotely controlled vehicle. The vehicle is designed with a modular structure, is adapted to perform the necessary surveillance functions and is sized to provide optimum manueverability and stability. A uniquely shaped chassis is sized to move easily through standard doorways, standard stairways, and narrow passages while having a length sufficient to provide both stability on inclined surfaces and maneuverability in confined spaces, such as landings. The vehicle is relatively lightweight and the chassis is designed to accommodate most of the weight at the lowest possible point in the body in order to provide an optimally low center of gravity which is displaced slightly forward of the center of the vehicle. The top deck of the vehicle is uniquely shaped and adapted to support any of several payloads mounted at a point forward to center of the vehicle. One such payload is an articulated arm module which comprises a turret containing an articulated arm capable of moving in pan and tilt and having a load affixed to its end which may provide visual, sampling or other sensing capabilities. The top cover, which is adapted to fit over the top of the chassis, slopes down toward the front and sides of the vehicle in order to permit a deployment of the payload in a manner that will augment the vehicle's climbing capabilities by further shifting the center of gravity to an optimum position. An independently-operated, motor-driven track is located on each of the two longitudinal sides of the vehicle; the tracks are adapted to provide motion in a forward, reverse and rotational direction. The tread is supported by wheels spaced along the bottom of the chassis and is driven by a motor controlled sprocket. A tensioner sprocket is used to provide the proper amount of flexibility to the tread for optimum traction over various types of surfaces. The tread itself is adapted to have maximum traction and is shaped to avoid being wedged in standard industrial surfaces such as drain grates and metal stairways.
The vehicle is adapted to have a plurality of payloads and payload mounts which provide flexibility in a wide variety of industrial applications. A standard payload includes a rotatable turret mounted on the vehicle deck and having an articulated arm for moving through a horizontal to a vertical direction. The arm is adapted to contain various loads, including television cameras, smear samplers and the like.
An object of the present invention is provision of a lightweight, maneuverable and optimally sized remote control vehicle for sensing the ambient conditions in hazardous environments.
A further object of the invention is to provide a remotely controlled vehicle which is free of power, telecommunications, command or control cabling.
Another object of the invention is the provision of remote control vehicle having on a top cover, a rotatable turret with an articulated arm and a useful payload at the end thereof and which is also adapted to be moved below the horizontal plane at which the turret joins the top cover, in order to provide a capability of shifting the center of gravity.
A further object of the invention is the provision of a remotely controlled vehicle having the capability of taking multiple smear samples from the surfaces of a hazardous environment facility.
Yet another object is the provision of a remotely controlled vehicle which is inexpensive to manufacture, easy to control and requires a minimum of maintenance and adjustment.
Another object of the invention is to provide a remotely controlled vehicle, having two parallel and independently driven track mechanisms, each disposed along the longitudinal sides and attached to run between the front and back of the vehicle, which is adapted to climb conventional stairways.